ILLUSTRATIONS 



Page 



Fig. 1. Minnesota Weed Seed Case Series 1 13 



2. Quack grass: three stages of seedling growth; also en- 



larged drawing of seed and spikelet 16 



3. Quack grass: mature plant above and below ground. ... 17 



4. Slender wheat grass: two stages of seedling growth; also 



enlarged drawing of seed and spikelet 18 



5. Slender wheat grass : mature plant and an enlarged spike. 19 



6. Yellow foxtail: three stages of seedling growth; also en- 



larged drawing of seed 20 



7. Yellow foxtail: mature plant 21 



8. Green foxtail: three stages of seedling growth; also en- 



larged drawing of seed 24 



9. Green foxtail: mature plant 25 



10. Wild oats: two stages of seedling growth; also enlarged 



drawing of seed 26 



1 1 . Wild oats : mature plant 27 



12. Curled dock: three stages of seedling growth; also en- 



larged drawing of seed and fruit 30 



13. Curled dock: mature plant 31 



14. Sheep sorrel: three stages of seedling growth; also en- 



larged drawing of seed 32 



15. Sheep sorrel: mature plant 33 



16. Smartweed: three stages of seedling growth; also en- 



larged drawing of seed 34 



17. Smartweed: mature plant 35 



18. Lamb's quarters: three stages of seedling growth; also 



enlarged drawing of seed and fruit 38 



19. Lamb's quarters: mature plant 39 



20. Pigweed: three stages of seedling growth; also enlarged 



drawing of seed 40 



2 1 . Pigweed : mature plant 41 



22. Russian thistle: three stages of seedling growth; also 



enlarged drawing of seed and fruit 42 



23. Russian thistle: branch of young plant; branch of mature 



plant and mature plant, showing general shape 43 



7 



